<template>
  <div class="app-container">
    <h2 style="text-align: center;">发布新课程</h2>
    <el-steps :active="1" process-status="wait" align-center style="marginbottom: 40px;">
      <el-step title="填写课程基本信息"/>
      <el-step title="创建课程大纲"/>
      <el-step title="最终发布"/>
    </el-steps>
    <el-form label-width="120px">
      <el-form-item label="课程标题">
        <el-input v-model="courseInfo.title" placeholder=" 示例：机器学习项目课：从基础到搭建项目视"/>
      </el-form-item>
      <!-- 所属分类 TODO -->
      <!-- 所属分类：级联下拉列表 -->
      <!-- 一级分类 -->
      <el-form-item label="课程类别">
        <el-select
            v-model="courseInfo.subjectParentId"
            placeholder="请选择" @change="getTwoSubject">
          <el-option
              v-for="subject in subjectNestedList"
              :key="subject.id"
              :label="subject.title"
              :value="subject.id"/>
        </el-select>
        <!-- 二级分类 -->
        <el-select v-model="courseInfo.subjectId" placeholder="请选择">
          <el-option
              v-for="subject in subSubjectList"
              :key="subject.value"
              :label="subject.title"
              :value="subject.id"/>
        </el-select>
      </el-form-item>
      <!-- 课程讲师 TODO -->
      <!-- 课程讲师 -->
      <el-form-item label="课程讲师">
        <el-select
            v-model="courseInfo.teacherId"
            placeholder="请选择">
          <el-option
              v-for="teacher in teacherList"
              :key="teacher.id"
              :label="teacher.name"
              :value="teacher.id"/>
        </el-select>
      </el-form-item>
      <el-form-item label="总课时">
        <el-input-number :min="0" v-model="courseInfo.lessonNum" controls-position="right" placeholder="数"/>
      </el-form-item>
      <!-- 课程简介 TODO -->
      <el-form-item label="课程简介">
        <tinymce :height="300" v-model="courseInfo.description"/>
      </el-form-item>
      <!-- 课程封面 TODO -->
      <el-form-item label="课程封面">
        <el-upload
            :show-file-list="false"
            :on-success="handleAvatarSuccess"
            :before-upload="beforeAvatarUpload"
            :action="BASE_API+'/eduoss/fileoss/upload'"
            class="avatar-uploader">
          <img :src="courseInfo.cover" style="height: 200px;width: 300px"/>
        </el-upload>
      </el-form-item>
      <el-form-item label="课程价格">
        <el-input-number :min="0" v-model="courseInfo.price" controls-position="right"/>
      </el-form-item>
      <el-form-item>
        <el-button :disabled="saveBtnDisabled" type="primary" @click="saveOrUpdate">保存并下一步</el-button>
      </el-form-item>
    </el-form>
  </div>
</template>
<script>
import course from "@/api/course";
import subject from "@/api/subject";
import Tinymce from '@/components/Tinymce'

export default {
  components: {Tinymce},
  data() {
    return {
      saveBtnDisabled: false, // 保存按钮是否禁用
      courseInfo: {
        title: '',
        teacherId: '',
        lessonNum: 0,
        description: '',
        cover: 'https://edu-zjh.oss-cn-beijing.aliyuncs.com/2021/07/14/8a9bf9340f9c44429ce5aa9f5593ee9a1.jpg',
        price: 0,
        subjectId: '',
        subjectParentId: '',
      },
      courseId: '',
      teacherList: [],
      subjectNestedList: [],//一级分类列表
      subSubjectList: [],//二级分类列表
      BASE_API: process.env.BASE_API, // 接口API地址
      key: ''
    }
  },
  watch: {
    $route(to, from) {
      this.init()
    }
  },
  created() {
    this.init()
    this.key = this.$route.params.key
  },
  methods: {
    init() {
      if (this.$route.params && this.$route.params.id) {
        this.courseId = this.$route.params.id
        this.getCourseInfo()
      } else {
        this.getTeacherName()
        this.getOneSubject()
      }
      if (this.courseInfo.id != null) {
        this.courseInfo = {
          title: '',
          teacherId: '',
          lessonNum: 0,
          description: '',
          cover: 'https://edu-zjh.oss-cn-beijing.aliyuncs.com/2021/07/14/8a9bf9340f9c44429ce5aa9f5593ee9a1.jpg',
          price: 0,
          subjectId: '',
          subjectParentId: '',
        }
      }
    },
    getTeacherName() {
      course.getAllTeacher().then(res => {
        this.teacherList = res.data.item;
      })
    },
    getOneSubject() {
      subject.getAllSubject().then(res => {
        this.subjectNestedList = res.data.list;
      })
    },
    getTwoSubject(value) {
      for (let i = 0; i < this.subjectNestedList.length; i++) {
        if (this.subjectNestedList[i].id === value) {
          this.subSubjectList = this.subjectNestedList[i].children
          this.courseInfo.subjectId = ''
        }
      }
    },
    handleAvatarSuccess(res, file) {
      console.log(res)// 上传响应
      console.log(URL.createObjectURL(file.raw))// base64编码
      this.courseInfo.cover = res.data.url
    },
    beforeAvatarUpload(file) {
      const isJPG = file.type === 'image/jpeg'
      const isLt2M = file.size / 1024 / 1024 < 2
      if (!isJPG) {
        this.$message.error('上传头像图片只能是 JPG 格式!')
      }
      if (!isLt2M) {
        this.$message.error('上传头像图片大小不能超过 2MB!')
      }
      return isJPG && isLt2M
    },
    getCourseInfo() {
      course.getCourseInfoById(this.courseId).then(res => {
        this.courseInfo = res.data.courseInfoVo
        subject.getAllSubject().then(res => {
          this.subjectNestedList = res.data.list
          for (let i = 0; i < this.subjectNestedList.length; i++) {
            var oneSubject = this.subjectNestedList[i]
            if (this.courseInfo.subjectParentId === oneSubject.id) {
              this.subSubjectList = oneSubject.children
            }
          }
        })
        this.getTeacherName()
      })
    },
    save() {
      course.getCourseInfo(this.courseInfo).then(res => {
        this.$message({
          type: "success",
          message: '添加课程信息成功！'
        })
        this.$router.push({path: '/course/chapter/' + res.data.courseId})
      })
    },
    update() {
      course.updateCourseInfoById(this.courseInfo).then(res => {
        this.$message({
          type: "success",
          message: '修改课程信息成功！'
        })
        this.$router.push({path: '/course/chapter/' + this.courseId})
      })
    },
    saveOrUpdate() {
      if (this.courseInfo.id == null) {
        this.save()
      } else {
        this.update()
      }
    },
  }
}
</script>
<style scoped>
.tinymce-container {
  line-height: 29px;
}
</style>